The Fowler's double sided Long Scale Calculator is a rare and unique scientific instrument from the 20th century.
It features a double-sided design, making it a versatile tool for a variety of scientific calculations.
Includes a soft leather case.
What makes this very unusual is the magnifying ring on the face. This makes it a rare premium or deluxe model.
With chrome knurled knobs and 72mm it dates it from 1948 to 1950 from my research.
Please see photos to work alongside this description.